[Serodiagnostic detection of IGA-specific antibodies in tuberculosis]

The objective of the submitted paper is evaluation of the possible use of detection of serum antibodies class IgA against the mycobacterial antigen Kp-90 ImCRA in the serodiagnostics of tuberculosis. Antibodies were detected by means of a commercially available IgA set Enzymimmunoassay Kreatech (Kreatech Diagnostics, Amsterdam, Netherlands). By means of the mentioned diagnostic kit antibodies class IgA were assessed in 26 patients with respiratory TB positive on microscopic examination and cultivation, 35 patients with tuberculosis of the lungs or extrapulmonary TB confirmed on cultivation and in 48 subjects with various clinical diagnoses, where TB was not confirmed clinically nor by bacteriological examination. In 64.3% of the patients with TB positive microscopical and cultivation optic density values (OD) higher than 1.2 were recorded, in 57% of these patients OD was higher than 1.5. The reactivity of patients in the control group (subjects with non-specific respiratory diseases) was strikingly low and all subjects with the exception of two had OD values lower than 1.2. The sensitivity of the test was 46.0%, the specificity 95.8%. The assembled results confirmed the reactivity of the majority of TB patients to mycobacterial antigen Kp-90 in the class of IgA serum antibodies and a low seroreactivity of controls with non-tuberculous affections of the airways where only two cases of high titres from a total of 48 examinations were recorded. The evaluated test--IgA Immunoassay Kreatech--thus extends the possibilities to detect the immunoreactivity of the patient when assessing the diagnosis and during the further follow up of the tuberculous finding.